Dynamo-electric machine



n. E. HELLMUND.

DYNAMO ELECTRIC MACHINE.

APPLlcATvloN FILED MAY1s,191e.

' WITNESSESZ Riga/f E. He//mwrd C l i MTQRNEYy DYNAMO-ELECTRIC MACHINESpecification of Letters Patent.

Patented Mar. 29, 1921.

Application ledvMay 16, 1916. Serial No. 97,837.

To all whomk t 'may concern.'

Be it known that I, RUDOLF E. HELL- MITND, a subject of the GermanEmperor, and a resident of Swissvale, in the county of Allegheny andState of Pennsylvania, have invented a new and useful Improvement inDynamo -Electric Machines, of which the following is a specification.

My invention relates to dynamo-electric machines, and it has particularrelation to systems of ventilation for such machines.

ne object of my invention is to provide an improved 'system of forcedventilation for motors of the semi-inclosed type that will insureuniform distribution of the cooling medium throughout the motor..

A further object of my inventlon 1s to provide a system of ventilationthat may be advantageously applied to motors which are arranged tooperate in pairs.

It has heretofore been proposed to provide the relatively rotatable coremembers of dynamo-electric machines with longitudinal ducts for thepassage of a cooling air. owever, when an external source was employedto create a circulation of the air, it was found that a greater volumeof air passed through the ducts in the stationary member than throughthe ducts in the rotating member. This resulted in undue heating of thelatter member. By my invention, I provide means for guiding and forcingthe air through the ducts in the rotatable member.

In the accompanying drawing, the figure is a transverse sectional viewof a motor embodying my invention, and comprises substantiallysemi-annular plates 1 and 2 between which is clamped a curved frame 3.An annular magnetizable core member 4 is composed of laminations and issecured between annular eud-plates 5 that are of somewhat greateroutside diameter than the laminations. The core member 4 is positionedon the frame 3 by spaced projections 6 provided on the inner surfacethereof which ft between the end-plates. The member 4 and the plates 5are provided with longitudinal passages 7, and additional longitudinalpassages 8 are provided by the spaces between the projections 6 and theouter surface of the core member 4. The frame 3 is provided with anopening 9 that s located adjacent to the left-hand end plate 5. A secondannular magnetizable core member 10 is composed of laminations and 1ssecured between end-plates 11 that are mounted on a spider 12. Thespider 12 is keyed to a shaft 13 that is rotatably mounted in bearings14 which are supported by the plates 1 and 2, respectively. The coremember 10 and the end-plates 11 are provided with longitudinal passages15. Additional longitudinal passages 15 are provlded between the web 12aof the spider 12 and the inner surface of the core member 10. A winding16 is located in suitable slots in the core member 10, and the endportions of the coils comprising the winding 16 are braced by an annularsupport 17. The coil-support 17 has an inner curved surface. andcircular plates 18, having curved surfaces similar to the inner surfaceof the support 17. are secured to the end plate 11 at pointsintermediate the passages 15. Substantially concentric passages 19 thatbend toward the shaft 13 are thus provided between the plates 18 and themember 17. The plates 18 are respectively provided along their inneredges with vanes 2O that project into the passages 19.

A casing 22. preferably formed ofsheet metal. incloses the upperportions of the motor.v The top plate 23 of the casing 22is supported bythe end-plates 5 of the core member 4, thus providing closed passages 24between the outer surfaces members 4 and the casing 22. plates 25 of thecasing 22 are supported by t e bearings 14 and are spaced from the endsof the winding 16 to provide chambers 26 and 27. opening 28 is providedat thetop of the chamber 26 at a point directly above the axis of themotor. The opening 28 is connected to suitable external means forcreating a circulation of air, such as fans 30. by means of tubes 31.

Having fully described the various parts of my device, the action of theventilating system during the operation of the motors is as follows:When the fans 30 are operated. airis forced into the chamber 26 and aportion thereof passes through the longitudinal passages 7 and 8 of thecore member 4. The remainder of the air is delivered to the passages 19where the rotation of the vanes 20 carried by the core member 10. actinin conjunction with the plates 18, sets the air into rotation and forcesit into the curved passages 19 at a slightly increased 'pressure andthrough the longitudinal passages 15. The air is discharged from thelongitudinal passages 15 into a collecting chamber and passes outside ofche frame 3 through the opening 9.

It is apparent from the foregoing that the Ventilating air is equallydistributed Within the motors and that continuous passage of the airthrough the rotating member is insured by the presence of the guidingpassages and vanes.

. I'Vhile I have shown my invention in a simple and preferred form, itis not so limited but is capable of various minor changes andmodifications Within the scope of the appended claims.

I claim as my invention:

1. In a. dynamo-electric machine, the combination With relativelyrotatable magnetizable members provided with longitudinal passages, andan inclosing casing for said members, of external means for creating acirculation of air through said machine, and further means locatedWithin said casing for setting the air into rotation and for slightlyraising the pressure thereof before entering the passages in therotatable member.

2. In a dynamo-electric machine, the combination With relativelyrotatable magnetizable members provided with longitudinal passages, andan inclosing casing for said member, of external means for creating acirculation of air through said machine and vanes carried by therotatable member and coacting barrier members for setting the air Withinsaid casing into rotation and for slightly raising the pressure thereofbefore entering the passages in said rotatable member. v

In testimony whereof I have hereunto subscribed my name this 29th day ofApril, 1916.

RDOLF E. HELLMUND.

